Alteration in expression of smooth muscle alpha-actin associated with transformation of rat 3Y1 cells.
Expression of actin was examined in a cultured rat embryonic cell line 3Y1 and transformed cell lines that originated from 3Y1. An alpha-actin in addition to cytoplasmic beta- and gamma-actins was detected in 3Y1 by two-dimensional gel electrophoresis. This alpha-actin was hardly detected at all in the transformants induced by Rous sarcoma virus, v-H-ras oncogene or adenovirus type 12, while the alpha-actin was retained in the transformed cell lines induced by N-methyl-N'-nitro-N-nitrosoguanidine or in SV40, which are cell lines of relatively low malignancy. Western and Northern blot analyses established that this alpha-actin was a smooth muscle alpha-isoform. An immunofluorescence study revealed that smooth muscle alpha-actin in 3Y1 cells is present in stress fibers. Thus, smooth muscle alpha-actin is also a component of actin stress fibers, as beta- and gamma-actins are in 3Y1 cells. An alteration in the expression of this actin isoform may be related to phenotypical changes accompanying transformation.
Okamoto-Inoue
M
M
Department of Experimental Cell Research, Kyushu University, Fukuoka, Japan.
Taniguchi
S
S
Sadano
H
H
Kawano
T
T
Kimura
G
G
Gabbiani
G
G
Baba
T
T
D000199:Actins / Q000096:biosynthesis*; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D005347:Fibroblasts / Q000166:cytology; D005455:Fluorescent Antibody Technique; D009132:Muscles / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D051381:Rats; D011916:Rats, Inbred F344
D000199:Actins; D004247:DNA